Download Design and Synthesis of a New Chelate for the Uranyl Ion

DESIGN AND SYNTHESIS OF A NEW CHELATE
FOR THE URANYL ION
Yael Alboa, Eric Maimona,b*, Israel Zilbermanna,b, Magal Saphiera,b, and Dan Meyersteina,c*
Chemistry Department, Ben Gurion University of the Negev, Beer Sheva, Israel
e-mail: [email protected]
Nuclear Research Centre Negev, Beer Sheva, Israel
Biological Chemistry Department, College of Judea and Samaria, Ariel, Israel
The hard acid, large uranyl cation is expected to form stable complexes with diamino tetradentate
dianionic open chain ligands. As the two axial position of the dioxo cation are occupied it was
decided to design a flexible ligand, which will be able to adjust itself to the coordination demands of
the central metal ion in the equatorial plane. Herein we report of a new chelate agent for the uranyl
cation – N,N’- di(2-hydroxy-4,6-di tertbutyl benzyl) imidazolidine. This tetradentate ligand is
expected to coordinate uranyl ion, leaving a free fifth equatorial coordination site for complexation
with an additional monodentate ligand. The ligand has been characterized by NMR and elemental
analysis. This ligand reacts instantaneously with uranyl ion to give a red solution with two
characteristic absorption bands in the visible region. Thus it was decided to examine the possibility
of development of a new quantitative spectrophotometric method for the determination of the uranyl
ion concentration in aqueous solutions. Preliminary experiments give encouraging results regarding
the possibility that this ligand can be used as reagent for the determination of uranyl ions’
concentrations in aqueous solutions, in the 5·10-5 M – 1.5·10-4 M concentration range, or as a
colorimetric sensor for determining the presence of uranyl ions in solution.